The order for the operation was issued by Oberkommando der Wehrmacht (OKW; Supreme Command of the Armed Forces) to Oberkommando des Heeres (OKH; Army High Command) and Oberkommando der Luftwaffe (OKL; Air Force High Command) on 6 February 1941. Two days later, the first units departed Naples for Africa and arrived on 11 February. On 14 February, the first units of the 5th Light Division (later renamed 21st Panzer Division) arrived in Tripoli, Libya. These units were the 3rd Reconnaissance Battalion and Tankhunter Unit 39; they were sent immediately to the front line at Sirte.

During the following months, more 5th Light Division units arrived, and in May the 15. Panzerdivision was embarked for North Africa.

A Panzer Mk II still in the dark grey paint scheme knocked out in the western desert.

While the tanks of the regiment were being loaded onto Italian cargo ships in the port of Naples, the cargo ship Leverkusen caught fire and sank, resulting in the loss of the 10 Panzer IIIs and three Panzer IVs on board. Ten replacement Panzer IIIs—a mixture of Ausf F and G models—were requisitioned from 6. Panzer-Regiment, and three newly built Panzer IV Ausf Es were shipped to Libya[2] between 10 and 14 April.[3] However, they did not reach the regiment until 29 April.[2]

A further 25 Panzer I Ausf A were shipped over to North Africa to reinforce the regiment arriving in Tripoli on 10 May.[2]

The on paper peak strength of the 5th Light Division in North Africa was therefore:

50 Panzer Is

45 Panzer IIs

71 Panzer IIIs

20 Panzer IVs

3 kleine Panzerbefehlswagens

4 Panzerbefehlswagens

All the tanks in 5. Panzer-Regiment were still painted dark grey (RAL 7021 dunkelgrau) and carried the 3. Panzerdivision's divisional emblem (inverted Y with two strikes)[4]

8. Panzer-Regiment was previously subordinate to the 10. Panzerdivision before being reassigned on 18 January to the newly created 15. Panzerdivision, itself created from the 33. Infanteriedivision.[2]

8. Panzer-Regiment was shipped across to North Africa in three convoys between 25 April and 6 May 1941. The regiment—146 tanks strong—consisted of 45 Panzer IIs, 71 Panzer IIIs, 20 Panzer IVs, four kleine Panzerbefehlswagens and six Panzerbefehlswagens. By 28 May, the entire regiment had assembled at the front.[5]

Following the fighting which had taken place from 1939 through 1940, the Heer was in the process of increasing the armour thickness to improve protection and survivability on all tank designs. New factory production tanks were built with increased armour thickness. For those tanks already in service, field modifications were made with armoured plates bolted onto the tanks to help increase their armor protection.

The majority, but not all, of the tanks from the 5. and 8. Panzer-Regiments shipped across to North Africa during Operation Sonnenblume had received these field modifications, though a small number had the added armor from the new factory production run.[6]

All tanks which were sent to North Africa were also modified for desert conditions, including improving the engine air cooling circulation, increasing the speed of the radiator and cutting holes into the hatch covers of the rear decks on the tanks.[6]